I've had a period of being somewhat obsessed with improving learning, mostly in the context of improving the performance of high-achieving math & CS students. Some random thoughts:

1. I loved this website.
2. I'm not sure that good memorization techniques are the most important learning tool for many (most?) fields.
3.  Also, it's likely that these aren't the major bottleneck for most people. I expect motivation and focus to be higher on the list. 
4. There's something interesting going on regarding Bloom's 2-sigma problem.
5. In a degree context, it might be important to identify the small number of important ideas/skills to learn that could best help with the rest of the degree and further on in life. 
6. Generally speaking, I'm not sure how important is learning quality during a degree (as opposed to high grades) when considering one's potential impact on the world. I have some worry that in practice, all one needs is to get through the door to a good career that they'd be motivated to engage in and learn on the job whatever they lacked from school. 
7. This reminds me a bit of this podcast, delivered by a psychologist interested in helping us to be more effective altruists. 

Some random thoughts from me as well:

• I wonder if different people may have quite different bottlenecks with regards to how to learn most effectively, and it may be not so much about "do these things" but rather "from these typical bottlenecks, which one affects you the most?"
• the framing of "The best way to learn" seems a bit dangerous to me; even if "scientifically proven", it still basically just means that it works well on average, but not necessarily for everybody. While active recall and spaced repitition probably are indeed very general, it might be good to add a few notes regarding how people might differ.
• on a similar note, 80,000 Hours tends to incorporate "reasons why you might disagree" or "where we've been wrong in the past" kind of sections and articles, which too I feel would help a little. E.g. "things Anki isn't ideal for", which definitely exist.
• maybe a relevant part of effective learning is to be more aware of one's true motives in doing things, be it getting a degree, reading non-fiction books, having an anki routine etc., and whether one's truly doing this to learn things, and if so for what exact purpose
• related to this, there are different dimensions to learning, similar to productivity: what are you learning (and why), how are you learning, and how much time are you spending. So basically direction, quality, quantity of the learning process. It seems that many resources, maybe including your site, mostly focus on the quality part, whereas the direction part may be even more important and comparably neglected.
• during one of the EAG Virtual conferences I talked to somebody who was involved in creating a free ebook on the most effective learning strategies for students during pandemic times; wasn't able to find it again so far, but if I do I'll add a link
• I personally would find it very useful to get some better/clearer mental models of learning and knowledge. Maybe the kind of thing Spencer Greenberg tends to do, e.g. in his podcasts, where he frequently goes into "Well I think X can be broken down into 4 categories: ..." mode and suddenly X makes way more sense than it did before that breakdown.
• for a long time I've been of the conviction that the way we tend to structure information is highly suboptimal. I'm mostly referring to linear texts about things. 1. Texts are good for some things, but by far not for everything, 2. we're not at all using our brain's immense capability for spatial and visual processing, 3. texts are static and non-interactive, 4. while you have things like table of contents, chapters/headlines and some formatting, it's not an ideal implementation of "different zoom levels", and there are certainly better ways of letting people learn things on a very high level first and then "zoom in" further. As a learner, you have to take what you've got of course. But the other side of the coin - how can you make learning for others easier as a content provider of any sort? - seems very important as well, and I think such a page would be in a great position to experiment with such ways, and not rely on classical linear text form.

About the concrete project:

• I think providing anki cards at the bottom of your posts is a great idea
• 80,000 Hours tends to have small summaries of their articles at the top, which I would find useful here as well
• The Key Ideas Guide post is currently very text-heavy, which makes sense since it's in progress and you probably want to focus on the ideas themselves rather than the presentation. For the future though I think it would make it much more digestible if there was a bit more variety to it, be it pictures, graphs, or even just some formatting tweaks. E.g. one or two screenshots from actual anki cars would be a start, or a graph of the forgetting curve.
• Style-wise, you're using parantheses a lot in your post, which I can totally relate with - I do it all the time e.g. when exchanging messages with people or writing forum posts and comments. But it does still seem sumoptimal to me, as it hurts the reading flow, and may be a sign one's not focusing on what's actually essential.
• The post to me feels quite a bit like it's trying to sell me something. I was almost expecting a "subscribe to my newsletter to get a FREE ebook!" while reading. :) This is something 80,000 Hours avoid pretty well by being very open and grayscale about things.
• I find it great that you've just started doing it and putting it out there looking for feedback; I'm working on one or two vague similar-ish projects (not related to learning though) and didn't yet manage to get over my semi-perfectionist "I'll just make sure I have something good before showing it to anybody" attitude, although I know that's a bad approach
• minor note, at one point you write "(god this bold is intense)" although there's nothing actually bold; maybe the formatting got lost somewhere on the way?

Some counter points on drawbacks/challenges of Anki:

• you need to be rather conscientous to use it effectively; missing a week can easily break the habit of daily ankiing, because you're suddenly looking at potentially 100s of flashcards to review
• it might push people to go for memorizing (often useless) facts rather than really learning and understanding deeper concepts
• also, adding anki cards to your deck now feels like progress; e.g. after reading a book (or chapter), you might have a feeling that not creating new cards is bad. This might nudge you to add useless cards rather than nothing, degrading the quality of your deck over time. I find it really hard to prevent this personally. After reading a book and going through my notes, if I add nothing to my Anki deck, I feel like having read the book was a waste of time. So I'm motivated to add things simply to feel better about the sunk cost. But looking at my deck honestly, I'm almost sure 50% of the stuff in there doesn't really add anything to my life.
• setting up such a system and getting into it takes a lot of work and willpower, and many people may just not be willing to go that far (even if it does indeed pay off in the long term)

That all being said, if I went back to university, I'd definitely use Anki and I'm sure it would improve my performance a lot compared to my time there in the past where I didn't know what spaced repetition even is. I'd just say that it's maybe something like 40% of my personal ideal learning system, and there would be a lot beyond that (e.g. how to watch lectures, how to take notes, how to work on actual exercises, the fact that explaining things to others is very helpful, how to motivate yourself, how to plan and build a reliable system, ...).

You (and others) might find these resources interesting:

https://www.lesswrong.com/posts/qLqyPMfc8epav72JF/learning-how-to-learn

https://www.lesswrong.com/posts/BzxbZqWoP9DRrznFi/learning-how-to-learn-and-20-studies

https://www.lesswrong.com/posts/37sHjeisS9uJufi4u/scholarship-how-to-do-it-efficiently